Unit 1 - Chapter 1 -Amino Acids Flashcards
Which anino acid does not have a primary amino group?
Proline. Proline has a secondary amino group.
What does each amino acid have?
Each amino acid has a carboxyl group, a primary/secondary amino group, and a distinctive side chain bounded to the “alpha”-carbon
How are amino acids bounded?
They are bounded together by peptide linkage
What is reffered to as imino acid?
Proline
What forms disulfide bounds?
Cysteine + cysteine = cystine
What determines the properties of the amino acids?
The side chain
Amino acids with nonpolar side chain:
- does not gain or lose protons
- does not participate in hydrogen or ionic bonds
- though of as “oily” or “lipid-like”
> hydrophobic interactions
Amino acids with nonpolar side chain:
- glycine
- alanine
- valine
- leucine
- isoleucine
- phenylalanine
- tryptophan
- methionine
- proline
Amino acids with uncharged polar side chain:
- serine
- threonine
- tyrosine
- asparigine
- glutamine
- cysteine
Amino acids with acidic side chain:
- aspartic acid
- glutamatic acid
Amino acids with basic side chain:
- histidine
- lysine
- arginine
Hydrophobic effect:
Hydrophobic effect is the result of the hydrophobicity of the nonpolar R groups, whoch act much like droplets of oil that coalesce In an aqueous enviroment.this happens to nonpolar AA
Sickle cell anemia
Sickle cell anemia, is a sickling disease of red blood cells, results from the replacement of polar glutamate with nonpolar valine at the 6th position in the “beta”-subunit of hemoglobin.
Give an example of where we can we find disulfide bonds?
- Many extracellular proteins are stabiblized by disulfide bonds.
- Albumin, a blood protein that functions as a transporter for a variety of molecules, is an example.
Which amino acids are proton donors?
Aspartic and glutamic acids
Which amino acids accept protons?
The side chains of the basic amino acids accept protons.
“Alpha”-carbon of the amino acids:
- is asymmetric
- is chiral or optically active
Which amino acid is not optically active (chiral)?
Glycine
Whoch forms can the amino acids exist in?
L and D form
Which form, L or D, is most common for the amino acid to exist in?
L form
Where can D-amino acids be found?
- some antibiotics
- bacterial cell walls
Henderson-Hasselbalch equation can be used_________
To calculate how the pH of a physiologic solution respond to changes in the concentraiton nof a weak acid and/or its corresponing “salt” form.
What leads to protein turn over?
Simultaneous synthesis and degradation
Amino acid pool is produced by __________
Degradation of protein
Amino acid pool is consumed by ________
Synthesis of body protein
How are amino acids bound together?
In proteins, amino acids are joined covalently by peptide bonds, which are amide linkages between the “alpha”-carboxyl group of one amino acid and the “alpha”-amino grouo of another.
Give examples on secondary structures:
- alpha-helix
- beta-sheet
- beta-bend (beta-turn)
What is the most common polypeptide helix?
Alpha-helix
Hydrogen bonds in the alpha-helix:
An alpha helix is stabilized by extensive hydrogen bonding between the peptide-bond carboxyl oxygens and amide hydrogens that are part of the poly peptide backbone.
How many amino acids does each turn of an alpha-helix contain?
3.6 amino acids
Which have more peptide chains: alpha-helix or beta-sheets?
Beta-sheets
Tertiary structures;
- disulfide bonds
- hydrophobic imteraction
- hydrogen bonds
- ionic interaction
- van der Waal
Amyloids
Are insoluble, spontaneously proteins
